Clear CMOS
Also searched as: clear cmos · cmos · reset bios · cmos battery · cmos jumper
What it means
The hardware reset for your motherboard's BIOS settings — it wipes them back to factory defaults. It's the escape hatch when a BIOS change stops the PC from booting.
More detail
CMOS is the tiny memory that holds your BIOS settings, kept alive by a coin battery on the board. You clear it with a dedicated button, a jumper, or by briefly pulling that battery with the PC unplugged. …
In the Blackbook
The deeper explanation continues inside the app. The Blackbook publishes its verdicts here — the full write-ups stay in the book, on your rig, next to your own measurements.
The Compy Blackbook holds 191 graded entries like this one, judged against your hardware — and every change it does make is reversible, with the receipt to prove it.
See Compy →